#!/usr/bin/env python3
# -*- coding: utf-8 -*-

class FooError(ValueError):
    """ FooError related error. """

    def __init__(self, *args, **kwargs):  # real signature unknown
        pass

    @staticmethod  # known case of __new__
    def __new__(*args, **kwargs):  # real signature unknown
        """ Create and return a new object.  See help(type) for accurate signature. """
        pass

def foo(s):
    n = int(s)
    if n == 0:
        raise FooError('invalid value:%s' % s)
    return 10 / n

foo('0')